Water heater/heat exchanger

[Horizonhunters98]

Hey everybody I've been scrolling through many of the posts looking to get some feedback on a heat exchanger idea off the engine coolant for a water heater I've been thinking about making my own from copper tubing I've seen a lot of Overlander vehicles do that for hot showers and it seems to work well. I was planning on building a large heat exchanger that runs off the coolant but adding a circulation pump to a 5 or 10 gallon insulated water tank that runs whenever the bus is running that way if the bus is running the water is circulating and staying warm so that way I could use the water off the block and the water in the tank. Any so inputs or ideas on it?

[CaptSquid]

Run with that idea. You'll have to have the rear heaters running in order for that heat exchanger to work, but it will give you a supply of hot water at the end of the day.